Plating barrel

ABSTRACT

A BARREL ESPECIALLY ADAPTED FOR USE IN PLATING, PHOSPHATING, CHEMICAL BRIGHTENING, WASHING AND SIMILAR OPERATIONS WHEREIN A QUANTITY OF WORKPIECES ARE PROCESSED IN A LIQUID BATH, THE BARREL HAVING A SIDE WALL FORMED WITH ROWS OF HOLES EXTENDING PARTIALLY THERETHROUGH FROM ONE SURFACE AND WITH A PLURALITY OF SLOTS EXTENDING PATRIALLY THERETHROUGH FROM THE OTHER SURFACE INTO COMMUNICATION WITH THE HOLES.

June 1, 1971 13 3,582,492

. PLATING BARREL Filed Feb. 12 1968 2 Sheets-Sheet 1 no.2 F|G.3

INVENTOR.

THOMAS RGILL BY W011), HOX FmQnnFSkULE}, Heinko.

ATTQ R N E Y5.

June 1, 1971 R GlLL 3,582,492

PLATING BARREL Filed Feb. 12. 1968 2 Sheets-Sheet I F IG 5 INVENTOR.

THOMAS R. GILL BY waflsJ-(oHmQmTismM-einh ATTQR N E Y5.

United States Patent Ofice Patented June 1, 1971 3,582,492 PLATlNG BARREL Thomas R. Gill, Pompano Beach, Fla., assignor to GS Equipment Company Filed Feb. 12, 1968, Ser. No. 704,902 Int. Cl. C23b 5/78 US. Cl. 204-413 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates generally to apparatus adapted for use in processing a quantity of articles in a liquid bath, and more particularly to the construction of barrels for use in electroplating operations and the like.

The conventional plating barrel is formed with a plurality of circulation holes which extend through its side wall from the inner to the outer surface. In most barrels the circulation holes vary from about of an inch in diameter up to about /2 of an inch in diameter or more depending upon the size of the parts to be processed in the barrel. The purpose of these holes is to permit the flow of electric current and the circulation of the treating liquid into and out of the barrel.

A problem which has been encountered in use of the conventional barrel has been the tendency of articles such as cotter pins, straight pins and the like either to lodge in the circulation holes or to escape through them into the liquid bath in which the barrel is immersed. In order to avoid this problem, the usual practice has been to use barrels having small diameter holes for treating small or straight articles.

The practice of using a barrel having small diameter holes has serious disadvantages, since the efiiceincy of the treating operation is directly dependent upon the open area afforded by the barrel openings. In electroplating operations, for example, a decrease in the open area afforded by the circulation holes restricts the flow of electric current and impairs the mixing or interchange of the plating solution in the barrel, thereby resulting in poor plating.

The use of barrels having small diameter holes also impairs drainage of the treating solution and presents a further problem known as solution drag-out and drag-in. Drag-out is costly, since it results in a loss of the relatively expensive solution trapped in the barrel and necessitates frequent addition of fresh solution to the bath. Further, drag-out presents waste disposal problems, since local codes require the waste solution to be treated with chemicals in order to avoid pollution. Solution drag-in can cause contamination of the different treating liquids in which a barrel may be successively immersed, and the contaminated baths must be frequently cleaned so as not to impair the efliciency of the treating operation.

SUMMARY OF THE INVENTION The present invention provides a new barrel construction which can be used to handle all sizes and shapes of articles during liquid treating operations, such as electroplating operations, without restricting either the flow of electric current or the circulation of liquid into and out of the barrel. More particularly, the invention provides a new barrel construction having circulation openings formed in its side wall in such a manner as to prevent the articles being processed from Working through the openings and escaping from the barrel. At the same time, the formation of the circulation openings in the new barrel is such as to permit unrestricted flow of electric current and liquid and to allow the liquid to drain freely from the barrel.

The foregoing advantages are attained and the disadvantages of the prior art are overcome in the preferred embodiment of the invention by a construction comprising rows of circulation holes which are formed partially through the side wall of the barrel from one surface. Rows of slots are formed partially through the side wall of the barrel from the opposite surface. The slots extend inwardly into communication with the holes to form the circulation openings through the barrel walls. The slots are parallel to the rows of holes and in the preferred embodiment each slot communicates a plurality of holes in a single row.

The holes can be of a size which was not practical in the conventional barrel when used to handle articles such as straight pins because of the tendency of such articles to work through the holes. In the new construction provided by this invention, the slots are formed in such a manner as to prevent the escape of slender and small articles through the large holes. For example, as hereinafter disclosed in detail, the slots may extend inwardly of the barrel side wall at an angle to the axes of the holes. Thus, while the ends of articles such as pins may enter the holes during rotation of the barrel, the articles are prevented from either lodging in the holes or passing completely through the side wall because of the angled slots.

While the slots which are formed in the barrel wall prevent articles from passing completely through the holes, the slots do not impair circulation of the liquid or the flow of current. Further, the slots do not impair the drainage characteristics of the barrel and therefore avoid the problems of solution drag-out and drag-in discussed above.

An additional advantage of the invention is that a single barrel can be used to handle all shapes and sizes of articles. It is not necessary to resort to special barrel constructions, particularly ones having small size holes, when processing articles such as straight pins and the like.

Accordingly, an object of the invention is to provide a new barrel for use in plating operations and the like characterized by a unique formation of the circulation openings which overcomes the problems and disadvantages of conventional barrels.

Another object of the invention is to provide a new barrel for use in plating operations and the like having uniquely formed circulation openings which resist the tendency of articles from passing therethrough and which at the same time provide for unrestricted flow of current and circulation of a treating liquid.

Still another object of the invention is to provide a new barrel for use in plating operations and the like having uniquely formed circulation openings which resist the tendency of articles to escape therethrough and which do not impair drainage of the treating liquid from the barrel, thereby avoiding the problems associated with solution drag-out and drag-in.

A more specific object of the invention is to provide a new barrel for use in plating operations and the like which has all of the advantages discussed above and is characterized by rows of holes formed partially through its side wall from one surface and slots formed partially through its side wall from the opposite surface into communication with the holes.

A further object of the invention is to provide a new barrel for use in plating operations and the like having rows of circulation holes formed partially therethrough from one surface, preferably the inner surface, and a plurality of slots formed partially through the opposite surface, preferably the outer surface, into communication with the holes, each of the slots being in communication With a plurality of holes in a row and extending inwardly at an angle to the axes of the holes communicating therewith.

Other objects and advantages and a fuller understanding of the invention will be had by reference to the following detailed description when taken in conjunction with the accompanying drawing.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, with a portion broken away, of a plating barrel embodying the present invention;

FIG. 2 is an enlarged, fragmentary portion of a side of the barrel shown in FIG. 1;

FIG. 3 is a cross-sectional view taken substantially on the line 33 of FIG. 2;

FIG. 4 is a fragmentary perspective view, partially in cross-section, of a barrel formed in accordance with a modified embodiment of the invention;

FIG. 5 is an enlarged, fragmentary portion of the barrel shown in FIG. 4; and

FIG. 6 is a cross-sectional view taken approximately on the line 6--6 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and to FIGS. 1-3 in particular, the plating barrel embodying a preferred embodiment of this invention is generally designated by reference numeral 10. The illustrated barrel 10 is of regular hexagonal cross-sectional shape and is comprised of a plurality of fixed side wall panels 11 and a removable cover panel 12 which provides access to the interior of the barrel. The removable cover panel 12 and each of the fixed side wall panels 11 are mounted between ribs 13 which extend between the ends of the barrel. The ends of the barrel 10 are closed by barrel heads 14 which can be secured to the ends of the panels 11 and the ribs 13 in any suitable manner, as by welding or cementing. As shown, the barrel heads 14 are provided with barrel hubs 15 having openings (not shown) through which, suitable electrodes can be inserted into the barrel in the usual manner.

The illustrated barrel 10 is adapted to be rotataby supported at its ends by suitable drive belts 16 which are engaged in peripheral belt grooves formed in the barrel heads 14. A more complete description of a beltsupported barrel of the type generally described is found in U.S. Pat. No. 2,886,505, issued May 12, 1959. The barrel 10 may be constructed of any material of suitable strength which will resist or can be protected against the corrosive action of the solutions encountered in use. Preferably, however, the barrel 10 is made of a corrosion resistant plastic material, such as polypropylene, polymethacrylate, polystyrene, or the like.

It is to be understood that the foregoing construction of the barrel 10 is not limiting of the present invention and that it has been chosen only for the purposes of disclosing one typical barrel structure to which the present invention has applicability. As will be apparent, the hereinafter described embodiment of the invention is equally applicable to other types and shapes of barrels, including barrels having more and less than six sides.

In accordance with the present invention, each of the fixed side wall panels 11 is formed with rows of circulation holes 20 which are drilled partially through the panel from one surface. Preferably, the holes 20 have their openings 21 on the inner surfaces of the panels 11 and terminate short of the outer surfaces thereof. Slots 22 are milled in the opposite surfaces of the panels 11, preferably the outer surfaces, parallel to rows of holes 20 and the slots extend inwardly of the panels into communication with the holes. As shown in FIGS. 1-3, the slots 22 extend longitudinally of the barrel 10 from one end of each of the panels 11 to the opposite end so that each slot communicates all of the holes in a longitudinal row. It will be understood, of course, that each of the slots 11 can be interrupted along its length so that in effect there are a plurality of slots which communicate tthe holes in a row. The slots 22 and the communicating holes 20 cooperate to provide circulation openings through the panels 11. If desired, the removable cover panel 12 can be formed in the same manner as the fixed side wall panels 11.

As generally discussed above, the slots 22 are formed in such a manner as to prevent objects such as pins and the like from working through the circulation openings and escaping from the barrel. In the illustrated and preferred construction, each of the slots 22 is formed so that it extends inwardly of the side wall panel 11 at an angle to the axes of the holes communicating with the slots. When the barrel is formed in this manner, it will be seen that the end of a slender object, such as shown at 25 in FIG. 3, may enter a hole 20 but cannot pass through the angled slot communicating therewith.

The width of the slots 22 and the particular angle on which they are formed relative to the axes of the holes 20 depends upon several interrelated factors, including the size of the parts to be processed, the size of the holes 20, and the depth of the holes in relation to the depth of the slots. For example, the slots 22 must be at a steep angle relative to the axes of the holes 20 when the diameter of the holes and the width of the slots are large in relation to the size of the parts. Conversely, when the diameter of the holes is small and/or when the slots are relatively narrow in comparison to the size of the articles processed in the barrel, the angle of the slots relative to the hole axes can be relatively small. In some instances, the slots 22 can be parallel to the axes of the holes, as when the diameter of the holes and/ or the 'width of the slots are sufficiently small to prevent any article in the barrel from passing through the circulation openings formed by the holes and slots. The angled formation of the slots 22 is preferred, however,'because it restricts the escape of slender articles while permitting the barrel to be formed with large holes and large slots in order to enhance current flow and circulation anddrainage of the treating liquid. The width of the slots is preferably smaller than the diameter of the holes, and as shown in FIG. 3 the angle formed by each slot relative to the axes of the communicating holes is such that the sides of the slot lie in planes which are spaced from the openings of the holes on the inner surface of the barrel wall. When the "sides of the slots are in planes spaced from the openings of the holes on the inner surface of the barrel wall, the resulting formation provides optimum resistance to the passage of articles through the circulation openings.

It will be apparent from the foregoing description that the objective of providing a barrel which can be used to process all sizes and shapes of parts, particularly small or slender parts such as straight pins, cotter pins and the like, has been attained through the cooperative-formation of the rows of holes 20 which are partially formed through the sides of the barrel and the slots 22 which are'parallel to the rows of holes and extend inwardly into communication therewith. At the same time, the rows ofholes 20 and the parallel slots 22 cooperate to define a substantial amount of open area through the wall of the barrel so as to promote the efficiency of the liquid treating operation.

In use the liquid of the treating bath enters the slots 22 and flows freely through the communicating holes 20 into the inside of the barrel. In'orde'r to further enhance the flow of liquid into the barrel, the angled and longitudinally extending slots 22 are preferably formed to open in the direction of barrel rotation. It is believed that this formation of the slots results in a pumping action in which the liquid is picked up in the slots and fed into the holes 20. When the barrel is removed from the liquid both, the liquid can freely drain from the barrel through the holes and communicating slots 22. Thus, the formation of the holes and the angled slots provide good drainage characteristics and thereby avoid the problems of solution drag-in and solution drag-out. The large open area provided by the holes and cooperating slots also promotes the flow of electric current through the barrel during plating operations.

Referring now to FIGS. 4-6, there is shown a plating barrel which is of the type more specifically disclosed in US. application, Ser. No. 614,439, now Pat. No. 3,439,900, of Thomas R. Gill, filed Feb. 7, 1967, and entitled Plating Barrel and Method of Fabrication. The barrel 30 is comprised of a one-piece side wall 31 which is horseshoe shaped in transverse cross-section, and circular barrel heads 32 (only one of which is shown) which close the ends of the barrel. A pair of ribs 33 are connected to the distal edges of the side wall 31 and are spaced apart to define a barrel opening adapted to be closed by a suitable, removable cover (not shown). The wall 31 is shown as being reinforced by additional spaced ribs 34. The ribs 33, 34 extend longitudinally of the barrel 30 and their ends are secured to the barrel heads 32.

In accordance with the invention, the barrel wall 31 is formed throughout its extent with rows of circulation holes which extend partially through the wall from one surface, preferably the inner surface. In this embodiment of the invention, the holes 40 in each row are aligned circumferentially of the barrel. The barrel wall 31 is also formed with spaced, circumferentially extending slots 42 which are milled into the surface of the wall opposite to the surface on which the holes 40 open. As shown, each of the slots 42 extends inwardly of the wall 31 into communication with all of the holes in a circumferential row, although it will be understood that each slot can be interrupted along its length so that a plurality of slots communicate the holes 40 in each row.

The holes 40 and the slots 42 are cooperatively formed in the same manner discussed above in conjunction with the embodiment of FIGS. 1-3 to prevent straight articles, such as shown at 45 in FIG. 6, from passing through the barrel openings defined by the holes and communicating slots. As in the previously described embodiment of the invention, the slots 42 are preferably formed so that each slot extends inwardly of the wall 31 at an angle to the axes of the holes communicating therewith. While the angle on which each slot is formed relative to the axes of the holes communicating therewith can be varied depending upon such factors as the size of the articles to be processed in the barrel, it is again preferred to form each slot so that its sides lie in planes spaced from the openings 41 of the holes that communicate with the slot.

Many modifications and variations of the invention will be apparent to those skilled in the art in the light of the foregoing detailed disclosure. Therefore, it is to be understood that, within the scope of the appended claims, the invention can be practiced otherwise than as specifically shown and described.

What is claimed is:

1. A barrel for processing a quantity of articles in a liquid bath, said barrel comprising side wall structure having inner and outer surfaces, spaced rows of circulation holes which open on one of said surfaces and terminate short of the other of said surfaces, and a plurality of slots which open on said other surface and extend into said wall structure into communication with said holes at oblique angles to the axes of the holes to form angled passageways extending between said surfaces.

2. A barrel as claimed in claim 1 wherein said slots extend longitudinally of said barrel.

3. A barrel as claimed in claim 1 wherein said slots extend circumferentially of said barrel.

4. A barrel as claimed in claim 1 wherein the width of said slots is less than the diameter of said holes.

5. A barrel as claimed in claim 1 wherein said slots and said holes are formed at an angle to each other such that the sides of each slot lie in planes which are spaced from the openings of the communicating holes on said one surface.

6. A barrel for use in processing a quantity of articles in a liquid bath, said barrel comprising side wall structure having rows of circulation holes formed partially through said side wall structure from its inner surface, said holes having openings on the inner surface of said side wall structure and terminating short of its outer surface, and a plurality of slots formed partially through said side wall structure from its outer surface and extending parallel to said rows of holes, each of said slots extending inwardly of said side wall structure into communication with a plurality of holes in a row at an oblique angle to the axes of the communicating holes to form angled passageways extending between said surfaces.

7. A barrel as claimed in claim 6 wherein each slot extends inwardly of said side wall structure at an angle to the axis of each communicating hole such that the sides of the slot lie in planes which are spaced from the openings of the communicating holes on the inner surface of said side wall structure.

8. A barrel as claimed in claim 7 wherein the width of each slot is less than the diameter of the communicating holes.

9. A barrel as claimed in claim 6 wherein said slots extend longitudinally of said barrel.

10. A barrel as claimed in claim 6 wherein said slots extend circumferentially of said barrel.

References Cited UNITED STATES PATENTS 2,243,728 5/1941 Davis 204-213 2,741,463 4/ 1956 Colclesser 204213X 3,153,624 10/ 1964 Jackson 204213 FOREIGN PATENTS 242,463 12/ 1960 Great Britain 2042l3 JOHN H. MACK, Primary Examiner W. SOLOMON, Assistant Examiner US. Cl. X.R. 134-153 

